Hydrogenated syndiotactic crystalline dicyclopentadiene ring-opening polymer

ABSTRACT

The present invention is a hydrogenated syndiotactic crystalline dicyclopentadiene ring-opening polymer having a melting point of 280° C. or higher and a syndiotacticity of higher than 90%, and a syndiotactic dicyclopentadiene ring-opening polymer, and a method for producing the syndiotactic dicyclopentadiene ring-opening polymer, and a method for producing the hydrogenated syndiotactic crystalline dicyclopentadiene ring-opening polymer, and a formed article, and a method for producing the formed article. One aspect of the invention provides a hydrogenated syndiotactic crystalline dicyclopentadiene ring-opening polymer having a high melting point of 280° C. or higher, and a syndiotacticity of higher than 90%.

TECHNICAL FIELD

The present invention relates to a hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer having high melting point andexcellent heat resistance, a syndiotactic dicyclopentadiene ring-openingpolymer that is excellent in solution stability after polymerizationreaction and can be converted to the hydrogenated product byhydrogenation reaction, and a production method thereof.

BACKGROUND ART

A hydrogenated ring-opening polymer of a norbornene-based monomer suchas dicyclopentadiene is a type of so-called cycloolefin polymer thatexhibits excellent transparency, low birefringence, formingprocessability and the like, and thus is used as a material that can beapplied to various applications such as optical applications.

A hydrogenated ring-opening polymer of dicyclopentadiene is normallyobtained in the form of an amorphous polymer that has an atacticstructure. However, the amorphous hydrogenated ring-opening polymer ofdicyclopentadiene having the atactic structure may exhibit insufficientheat resistance, mechanical strength, solvent resistance and the likedepending on the application. Hence, in order to improve the performanceof such a hydrogenated ring-opening polymer, a hydrogenated ring-openingpolymer of dicyclopentadiene that has crystallinity obtained byproducing a hydrogenated ring-opening polymer of dicyclopentadienehaving a tactic structure on its main chain has been proposed.

For example, Patent Literature 1 discloses that a dicyclopentadienering-opening polymer having cis-syndio regularity that is soluble in ahydrocarbon solvent such as a cyclohexane at room temperature isobtained by subjecting dicyclopentadiene to ring-opening polymerizationusing a polymerization catalyst that mainly includes a group 6transition metal compound having a specific substituent such as aphenylimidotungsten tetrachloride diethyl ether complex, and furthermorea hydrogenated syndiotactic crystalline dicyclopentadiene ring-openingpolymer having crystallinity is obtained by hydrogenating thecarbon-carbon double bonds included in the ring-opening polymer using amixture of a bis(tricyclohexylphosphine)benzylideneruthenium(IV)dichloride and ethyl vinyl ether or the like, as a hydrogenationcatalyst. In addition, Patent Literature 2 discloses that a crystallinedicyclopentadiene ring-opening polymer having cis-iso regularity that isinsoluble in a hydrocarbon solvent such as cyclohexane at roomtemperature is obtained by subjecting dicyclopentadiene to ring-openingpolymerization using a polymerization catalyst that mainly includes agroup 4 to 6 transition metal compounds that include a specific aromaticdioxy group as a ligand such as a phenylimidotungsten bisphenolatecomplex, and a hydrogenated isotactic crystalline dicyclopentadienering-opening polymer having crystallinity is obtained by hydrogenatingthe carbon-carbon double bonds included in the ring-opening polymerusing RuHCl(CO) (PPh₃)₂ or the like as a hydrogenation catalyst.

CITATION LIST Patent Literature

Patent Literature 1: JP-A-2005-089744 (US2007/0185290A1)

Patent Literature 2: JP-A-2013-139513

SUMMARY OF INVENTION Technical Problem

A review by the present inventor about the hydrogenated syndiotacticcrystalline dicyclopentadiene ring-opening polymer specificallydescribed in Patent Literature 1 indicated that this hydrogenatedsyndiotactic crystalline dicyclopentadiene ring-opening polymer had amelting point as high as about 270° C., but it began to soften (melt)from lower than 260° C. when the polymer was heated, and thus asubstantial upper temperature limit was lower than 260° C.

Meanwhile, the hydrogenated isotactic crystalline dicyclopentadienering-opening polymer specifically described in Patent Literature 2, itsisotacticity was 100% within the measurement accuracy for the analyzer,and its melting point was about 295° C. which is extremely high.However, the dicyclopentadiene ring-opening polymer having acis-isotactic structure was insoluble in a hydrocarbon solvent such ascyclohexane at room temperature, and thus the polymer was difficult toproduce in an industrial production scale.

Thus, an object of the present invention is to provide a hydrogenatedsyndiotactic crystalline dicyclopentadiene ring-opening polymer having asufficiently high melting point, excellent heat resistance andadvantageous industrial producibility, a syndiotactic dicyclopentadienering-opening polymer that is excellent in solution stability afterpolymerization reaction and can be converted into the hydrogenatedproduct by hydrogenation reaction, and an efficient production methodthereof.

Solution to Problem

As a result of extensive studies to achieve the above object, thepresent inventor has found that a dicyclopentadiene ring-opening polymersoluble in a hydrocarbon solvent at room temperature can be obtained bysubjecting dicyclopentadiene to ring-opening polymerization using apolymerization catalyst including a tungsten compound having aparticular structure, and a hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer having an extremely high meltingpoint can be obtained by hydrogenating a carbon-carbon double bond inthis dicyclopentadiene ring-opening polymer. The present invention hasbeen completed on the basis of these findings.

Thus, one aspect of the invention provides the followings: (1) ahydrogenated syndiotactic crystalline dicyclopentadiene ring-openingpolymer, (2) a syndiotactic dicyclopentadiene ring-opening polymer, (3)a method for producing the syndiotactic dicyclopentadiene ring-openingpolymer, (4) a method for producing a hydrogenated syndiotacticcrystalline dicyclopentadiene ring-opening polymer, (5) a formed articleof the hydrogenated syndiotactic crystalline dicyclopentadienering-opening polymer, and (6) a method for producing the formed article.

[1] A hydrogenated syndiotactic crystalline dicyclopentadienering-opening polymer having a melting point of 280° C. or higher and asyndiotacticity of higher than 90%.

[2] A syndiotactic dicyclopentadiene ring-opening polymer, which canproduce the hydrogenated syndiotactic crystalline dicyclopentadienering-opening polymer according to [1] by hydrogenation reaction, and hasa syndiotacticity of higher than 90%.

[3] A method for producing the syndiotactic dicyclopentadienering-opening polymer according to [2], which includes a step ofsubjecting dicyclopentadiene to ring-opening polymerization using apolymerization catalyst including a tungsten compound represented by thefollowing formula (1):

wherein W represents a tungsten atom;

each of R¹ and R² independently represents a group selected from ahydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl grouphaving 6 to 12 carbon atoms that may have a substituent, and acycloalkyl group having 3 to 20 carbon atoms that may have asubstituent;

L¹ represents a nitrogen atom that may have a substituent, selected froman alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12carbon atoms that may have a substituent, and a cycloalkyl group having3 to 20 carbon atoms that may have a substituent;

L² represents a conjugated heterocyclic group having 5 to 15-memberedrings that includes at least one nitrogen atom, and the conjugatedheterocyclic group may have a substituent;

L³ represents an alkoxy group represented by O—R³, where R³ represents agroup selected from an alkyl group having 1 to 12 carbon atoms that mayhave a substituent, and an aryl group having 6 to 30 carbon atoms thatmay have a substituent; and

L⁴ represents a neutral conjugated heterocyclic ligand having at leasttwo nitrogen atoms and having 12 to 24-membered rings, where theconjugated heterocyclic ligand may have a substituent.

[4] A method for producing the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer according to [1] including a stepof subjecting the syndiotactic dicyclopentadiene ring-opening polymeraccording to [2] to hydrogenation reaction.

[5] A formed article including the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer according to [1].

[6] A method for producing the formed article according to [5],including a step of forming the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer according to [1].

In the present description, “may have a substituent” means “beingunsubstituted or having a substituent”.

Advantageous Effects of Invention

One aspect of the invention provides a hydrogenated syndiotacticcrystalline dicyclopentadiene ring-opening polymer having a high meltingpoint of 280° C. or higher, and a syndiotacticity of higher than 90%.

DESCRIPTION OF EMBODIMENTS

The present invention provides a hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer having a melting point of 280° C.or higher and a syndiotacticity of higher than 90% (hereinafter referredto as “hydrogenated crystalline dicyclopentadiene ring-opening polymeraccording to one embodiment of the invention” in some cases).

The hydrogenated crystalline dicyclopentadiene ring-opening polymeraccording to one embodiment of the invention includes repeating a unitof a hydrogenated poly(endo-dicyclopentadiene) represented by thefollowing formula (2).

The melting point of the hydrogenated crystalline dicyclopentadienering-opening polymer according to one embodiment of the invention is280° C. or higher, and preferably 282° C. or higher. The melting pointin the present invention means a melting point determined after thehydrogenated crystalline dicyclopentadiene ring-opening polymer has beenonce sufficiently molten and then sufficiently crystallized. The upperlimit of the melting point is not particularly limited, butapproximately 310° C. In the present invention, the melting point can bemeasured in accordance with the method described in the followingExamples.

The initial melting temperature of the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention is preferably 260° C. or higher, and more preferably 265°C. or higher. The upper limit of the initial melting temperature is notparticularly limited, but is approximately 310° C. and equal to or lowerthan the melting point. Since the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention has a considerably high initial melting temperature, ithas excellent processability such as solder reflow resistance.

The hydrogenated crystalline dicyclopentadiene ring-opening polymeraccording to one embodiment of the invention has a tacticity, becausethe carbon represented by (1, 4) in the above formula (2) is anasymmetric carbon (indicated by *).

The hydrogenated crystalline dicyclopentadiene ring-opening polymeraccording to one embodiment of the invention is a polymer that hassyndiotacticity where the syndiotacticity i.e. a ratio of racemo diadsrelative to the total of meso diads and racemo diads in the stericconfiguration (hereinafter may be simply referred to as “ratio of racemodiads” in some cases) is higher than 90%. In the hydrogenatedcrystalline dicyclopentadiene ring-opening polymer according to oneembodiment of the invention, the ratio of the racemo diads is preferablyhigher than 91%, and more preferably higher than 92%.

When the ratio of the racemo diads is 90% or less, the crystallinity ofthe hydrogenated syndiotactic crystalline dicyclopentadiene ring-openingpolymer is greatly decreased, and the high melting point and theproperties such as processability are impaired.

Specifically, the syndiotacticity can be determined by the formula I:[(racemo diads)/(meso diads+racemo diads)×100(%)]. The ratio of theracemo diads can be calculated by analyzing ¹³C-NMR spectrum for thehydrogenated syndiotactic crystalline dicyclopentadiene ring-openingpolymer. Specifically, the ratio can be determined by quantitativelymeasuring the spectrum of the carbon atoms indicated by (5, 9) in theabove formula (2) of the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention. That is, the ¹³C-NMR spectrum measurement for the carbonatoms indicated by (5, 9) included in the repeating unit represented bythe above formula (2) may be carried out in ano-dichlorobenzene-d₄/trichlorobenzene [mixing ratio (weight basis): 1/2]mixed solvent at 200° C., and a peak area value of the signal attributedto the meso diads at 43.35 ppm and a peak area value of the signalattributed to the racemo diads at 43.43 ppm are substituted into theabove formula 1 to determine the ratio of the racemo diads.

The hydrogenated crystalline dicyclopentadiene ring-opening polymer andthe dicyclopentadiene ring-opening polymer according to one embodimentof the invention have a repeating unit derived from dicyclopentadienerepresented by the following formula (3).

From the viewpoint that the syndiotactic dicyclopentadiene ring-openingpolymer (hereinafter referred to as “dicyclopentadiene ring-openingpolymer” in some cases) and the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention particularly improve the heat resistance of thehydrogenated product and accelerate its crystallization rate, it ispreferable to use a polymer including a large number ofdicyclopentadiene-derived repeating units. The ratio of thedicyclopentadiene-derived repeating units relative to all repeatingunits in the hydrogenated crystalline dicyclopentadiene ring-openingpolymer and the dicyclopentadiene ring-opening polymer according to oneembodiment of the invention is not particularly limited, but ispreferably 90 wt % or higher, more preferably 95 wt % or higher, andparticularly preferably 97 wt % or higher.

As mentioned below, the hydrogenated crystalline dicyclopentadienering-opening polymer according to one embodiment of the invention can beefficiently obtained by a process where dicyclopentadiene or a monomermixture including dicyclopentadiene and other cycloolefin monomers(hereinafter whole of them is referred to as “dicyclopentadiene and thelike” in some cases) is subjected to ring-opening polymerization in thepresence of a specific ring-opening polymerization catalyst to obtain adicyclopentadiene ring-opening polymer, which is then hydrogenated.

The dicyclopentadiene includes endo and exo stereoisomers, and both ofthem can be used as a monomer, either of which can be used alone, or astereoisomer mixture including the endo and exo stereoisomers in anyratio can be used. From the viewpoint of increasing the crystallinity ofthe hydrogenated crystalline dicyclopentadiene ring-opening polymer andparticularly improving its heat resistance, it is preferable to increasethe ratio of one stereoisomer. The ratio of the endo or exo stereoisomerto be used is preferably 90% or higher, more preferably 95% or higher,and particularly preferably 99% or higher. Additionally, from theviewpoint of easiness of synthesis, it is preferable that thestereoisomer of which the ratio is increased, is the endo stereoisomer.

In the production of the dicyclopentadiene ring-opening polymeraccording to one embodiment of the invention, dicyclopentadiene may beused in combination with other cycloolefin monomers. The amount of othercycloolefin monomers to be used is less than 10 wt %, preferably lessthan 3 wt %, and more preferably less than 1 wt % based on the totalamount of dicyclopentadiene and other cycloolefin monomers.

Examples of other cycloolefin monomers that can be used in combinationwith dicyclopentadiene include the followings:

cycloalkenes such as cyclopentene, cyclohexene and cycloheptane;

dicyclopentadienes such as tricyclo[4.3.1^(2,5).0]dec-3-ene andtricyclo[4.4.1^(2,5).0]undec-3-ene obtained by saturating thedicyclopentadiene or the double bond of the 5-membered ring moietyincluded in dicyclopentadiene;

norbornenes unsubstituted or having an alkyl group as a substituent,such as norbornene, 5-methylnorbornene, 5-ethylnorbornene,5-butylnorbornene, 5-hexylnorbornene, 5-decylnorbornene,5-cyclohexylnorbornene and 5-cyclopentylnorbornene;

norbornenes having an alkenyl group as a substituent, such as5-ethylidenenorbornane, 5-vinylnorbornene, 5-propenylnorbornene,5-cyclohexenylnorbornene and 5-cyclopentenylnorbornene;

norbornenes having an aromatic ring as a substituent, such as5-phenylnorbornene;

norbornenes having an oxygen atom-containing polar group, such as5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene,5-methyl-5-methoxycarbonylnorbornene,5-methyl-5-ethoxycarbonylnorbornene, norbornenyl-2-methyl propionate,norbornenyl-2-methyl octanoate, norbornene-5,6-dicarboxylic anhydride,5-(hydroxymethyl)norbornene, 5,6-di(hydroxymethyl)norbornene,5,5-di(hydroxymethyl)norbornene, 5-hydroxy-1-propylnorbornene,5,6-dicarboxynorbornene, and 5-methoxycarbonyl-6-carboxynorbornene; and

norbornenes having a nitrogen atom-containing polar group, such as5-cyanonorbornene and norbornene-5,6-dicarboxylic acid imide.

In addition, examples of tetracyclododecenes other thantetracyclododecene include the following: a tetracyclododecene having analkyl group as a substituent, such as 8-methyltetracyclododecene,8-ethyltetracyclododecene, 8-cyclohexyltetracyclododecene and8-cyclopentyltetracyclododecene;

tetracyclododecenes having a double bond outside the ring, such as8-methylidenetetracyclododecene, 8-ethylidenetetracyclododecene,8-vinyltetracyclododecene, 8-propenyltetracyclododecene,8-cyclohexenyltetracyclododecene, and 8-cyclopentenyltetracyclododecene;

tetracyclododecenes having an aromatic ring, such as8-phenyltetracyclododecene;

tetracyclododecenes having an oxygen atom-containing substituent, suchas 8-methoxycarbonyltetracyclododecene,8-methyl-8-methoxycarbonyltetracyclododecene,8-hydroxymethyltetracyclododecene, 8-carboxytetracyclododecene,tetracyclododecene-8,9-dicarboxylic acid, andtetracyclododecene-8,9-dicarboxylic anhydride;

tetracyclododecenes having a nitrogen atom-containing substituent, suchas 8-cyanotetracyclododecene and tetracyclododecene-8,9-dicarboxylicacid imide;

tetracyclododecenes having a halogen atom-containing substituent, suchas 8-chlorotetracyclododecene; and

tetracyclododecenes having a silicon atom-containing substituent, suchas 8-trimethoxysilyltetracyclododecene.

Examples of hexacycloheptadecenes include the followings:hexacycloheptadecenes unsubstituted or having an alkyl group as asubstituent, such as hexacycloheptadecene,12-methylhexacycloheptadecene, 12-ethylhexacycloheptadecene,12-cyclohexylhexacycloheptadecene and12-cyclopentylhexacycloheptadecene;

hexacycloheptadecenes having a double bond outside the ring, such as12-me thylidenehexacycloheptadecene, 12-ethylidenehexacycloheptadecene,12-vinylhexacycloheptadecene, 12-propenylhexacycloheptadecene,12-cyclohexenylhexacycloheptadecene and12-cyclopentenylhexacycloheptadecene;

hexacycloheptadecenes having an aromatic ring as a substituent, such as12-phenylhexacycloheptadecene;

hexacycloheptadecenes having an oxygen atom-containing substituent, suchas 12-methoxycarbonylhexacycloheptadecene, 12-methyl-12-methoxycarbonylhexacycloheptadecene, 12-hydroxymethylhexacycloheptadecene,12-carboxyhexacycloheptadecene, hexacycloheptadecene-12,13-dicarboxylicacid and hexacycloheptadecene-12,13-dicarboxylic anhydride;

hexacycloheptadecenes having a nitrogen atom-containing substituent,such as 12-cyanohexacycloheptadecene andhexacycloheptadecene-12,13-dicarboxylic acid imide;

hexacycloheptadecenes having a halogen atom-containing substituent, suchas 12-chlorohexacycloheptadecene;

hexacycloheptadecenes having a silicon atom-containing substituent, suchas 12-trimethoxysilylhexacycloheptadecene; and

tetracyclo[6.5.1^(2,5).0^(1,6).0^(8,13)]trideca-3,8,10,12-tetraene (alsoreferred to as 1,4-methano-1,4,4a,9a-tetrahydrofluorene);tetracyclo[6.6.1^(2,5).0^(1,6).0^(8,13)]tetradeca-3,8,10,12-tetraene(also referred to as 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene);and the like.

The number average molecular weight (Mn) of the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention is normally 500 to 1,000,000, preferably 1000 to 600,000,and more preferably 2000 to 400,000. If the Mn is too low, themechanical strength may be decreased, and if the Mn is too high, thepolymer tends to be difficult to be formed. Note that the number averagemolecular weight of the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer is approximately equal to that ofthe dicyclopentadiene ring-opening polymer before the hydrogenationprocess.

The glass transition temperature (Tg) of the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention is preferably 80° C. or higher, more preferably 85° C. orhigher. If the glass transition temperature is within these ranges, thepolymer is favorable because of improved heat resistance e.g. highdeflection temperature under load. The upper limit of the glasstransition temperature is not particularly limited, but is approximately120° C.

The dicyclopentadiene ring-opening polymer according to one embodimentof the invention can be obtained by subjecting dicyclopentadiene and thelike to ring-opening polymerization using a polymerization catalystincluding a tungsten compound represented by the following formula (1).

In the formula (1), W represents a tungsten atom.

Each of R¹ and R² independently represents a group selected fromhydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl grouphaving 6 to 12 carbon atoms that may have a substituent, and acycloalkyl group having 3 to 20 carbon atoms that may have asubstituent.

L¹ represents nitrogen atom that may have a substituent selected from analkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12carbon atoms that may have a substituent and a cycloalkyl group having 3to 20 carbon atoms that may have a substituent.

L² represents a conjugated heterocyclic group having at least onenitrogen atom and having 5 to 15-membered rings, where the conjugatedheterocyclic group may have a substituent.

L³ represents an alkoxy group represented by O—R³, where R³ represents agroup selected from an alkyl group having 1 to 12 carbon atoms that mayhave a substituent and an aryl group having 6 to 30 carbon atoms thatmay have a substituent.

L⁴ represents a neutral conjugated heterocyclic ligand having at leasttwo nitrogen atoms and having 12 to 24-membered rings, where theconjugated heterocyclic ligand may have a substituent.

That is, in the production method according to one embodiment of theinvention, the tungsten compound represented by the above formula (1) isused as a polymerization active component of a polymerization catalystfor ring-opening polymerization of dicyclopentadiene and the like.

In the above formula (1), W represents a tungsten atom.

Each of R¹ and R² independently represents a hydrogen atom; an alkylgroup having 1 to 12 carbon atoms such as a methyl group, an ethylgroup, a n-propyl group, an isopropyl group, a n-butyl group, anisobutyl group and a t-butyl group; a cycloalkyl group having 3 to 20carbon atoms that may have a substituent, such as a cyclopropyl group, acyclopentyl group, a cyclohexyl group; or an aryl group having 6 to 12carbon atoms that may have a substituent. Examples of an aryl group ofthe aryl group that may have a substituent include a phenyl group, a1-naphthyl group, a 2-naphthyl group and the like. In addition, examplesof the substituent for the cycloalkyl group and the aryl group includean alkyl group having 1 to 12 carbon atoms such as a methyl group and anethyl group; a halogen atom such as a fluorine atom, a chlorine atom anda bromine atom; an alkoxy group having 1 to 12 carbon atoms such as amethoxy group, an ethoxy group and an isopropoxy group; a haloalkylgroup having 1 to 12 carbon atoms such as a trifluoromethyl group; ahaloalkoxy group having 1 to 12 carbon atoms such as a trifluoromethoxygroup; an aryl group having 6 to 12 carbon atoms that may have asubstituent, such as a phenyl group, a 4-methylphenyl group, a2,4-dimethylphenyl group, a 2-chlorophenyl group and a 3-methoxyphenylgroup; and the like.

L¹ represents nitrogen atom that may have a substituent selected from analkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12carbon atoms that may have a substituent and a cycloalkyl group having 3to 20 carbon atoms that may have a substituent.

The alkyl group having 1 to 12 carbon atoms included in the nitrogenatom of the L¹ may be either linear or branched. Specific examplesthereof include a methyl group, an ethyl group, a propyl group, anisopropyl group, a butyl group, a t-butyl group, a pentyl group, a hexylgroup and the like.

Examples of the aryl group having 6 to 12 carbon atoms include a phenylgroup, a 1-naphthyl group and a 2-naphthyl group and the like.

Examples of the cycloalkyl group having 3 to 20 carbon atoms include acyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctylgroup, an adamantyl group and the like.

The substituent present in nitrogen atom of the L¹, that may be includedin the cycloalkyl group having 3 to 20 carbon atoms and the aryl grouphaving 6 to 12 carbon atoms is not particularly limited. Examples of thesubstituent include an alkyl group having 1 to 12 carbon atoms such as amethyl group and ethyl group; halogen atom such as fluorine atom,chlorine atom and bromine atom; an alkoxy group having 1 to 12 carbonatoms such as a methoxy group, an ethoxy group and an isopropoxy group;a haloalkyl group having 1 to 12 carbon atoms such as a trifluoromethylgroup; a haloalkoxy group having 1 to 12 carbon atoms such astrifluoromethoxy group; an aryl group having 6 to 12 carbon atoms thatmay have a substituent, such as phenyl group, 4-methylphenyl group,2,4-dimethylphenyl group, 2-chlorophenyl group and 3-methoxyphenylgroup; an amino group; a monosubstituted amino group such as methylaminogroup; a disubstituted amino group such as dimethylamino group; an iminogroup; and the like.

Specific examples of the aryl group having 6 to 12 carbon atoms that mayhave a substituent include a phenyl group, a 2-methylphenyl group, a2,6-dimethylphenyl group, a 3,5-dimethylphenyl group, apentafluorophenyl group and the like.

L² represents a conjugated heterocyclic group having at least onenitrogen atom and having 5 to 15-membered rings, that may have asubstituent.

Examples of the conjugated heterocyclic group of L² include a 5-memberedring conjugated heterocyclic group such as a pyrrolyl group, animidazolyl group, a pyrazolyl group, an oxazolyl group, and a thiazolylgroup; a 6-membered ring conjugated heterocyclic group such as a pyridylgroup, a pyridazinyl group, a pyrimidinyl group, a pyrazinyl group and atriazinyl group; a fused ring conjugated heterocyclic group such as aquinazolinyl group, a phthalazinyl group and a pyrrolopyridyl group; andthe like.

The substituent that may be included in the conjugated heterocyclicgroup is not particularly limited. Its examples include an alkyl grouphaving 1 to 12 carbon atoms such as a methyl group and an ethyl group; ahalogen atom such as a fluorine atom, a chlorine atom and a bromineatom; an alkoxy group having 1 to 12 carbon atoms such as a methoxygroup, an ethoxy group and an isopropoxy group; a haloalkyl group having1 to 12 carbon atoms such as a trifluoromethyl group; a haloalkoxy grouphaving 1 to 12 carbon atoms such as a trifluoromethoxy group; an arylgroup having 6 to 12 carbon atoms that may have a substituent, such as aphenyl group, a 4-methylphenyl group, a 2,4-dimethylphenyl group, a2-chlorophenyl group and a 3-methoxyphenyl group; an amino group; amonosubstituted amino group such as a methylamino group; a disubstitutedamino group such as a dimethylamino group; an imino group; and the like.

L³ is a group represented by —O—R³. R³ is a group selected from an alkylgroup having 1 to 12 carbon atoms that may have a substituent and anaryl group having 6 to 30 carbon atoms that may have a substituent.

Examples of the alkyl group having 1 to 12 carbon atoms among the alkylgroup having 1 to 12 carbon atoms that may have a substituent of the R³′include a methyl group, an ethyl group, a propyl group, an isopropylgroup, a butyl group, a t-butyl group, a pentyl group and the like.

The substituent that may be included in the alkyl group having 1 to 12carbon atoms of the R³ is not particularly limited. Its examples includea halogen atom such as a fluorine atom, a chlorine atom and a bromineatom; an alkoxy group having 1 to 12 carbon atoms such as a methoxygroup, an ethoxy group and an isopropoxy group; a haloalkyl group having1 to 12 carbon atoms such as a trifluoromethyl group; a haloalkoxy grouphaving 1 to 12 carbon atoms such as a trifluoromethoxy group; an arylgroup having 6 to 12 carbon atoms that may have a substituent, such as aphenyl group, a 4-methylphenyl group, a 2,4-dimethylphenyl group, a2-chlorophenyl group and a 3-methoxyphenyl group; an amino group; amonosubstituted amino group such as a methylamino group; a disubstitutedamino group such as a dimethylamino group; an imino group; and the like.

Examples of the aryl group having 6 to 30 carbon atoms among the arylgroup having 6 to 30 carbon atoms that may have a substituent, include aphenyl group, a 1-naphthyl group, a 2-naphthyl group, an adamantyl groupand the like.

The substituent that may be included in the aryl group having 6 to 30carbon atoms of the R³ is not particularly limited. Its examples includea halogen atom such as a fluorine atom, a chlorine atom and a bromineatom; an alkyl group having 1 to 12 carbon atoms such as a methyl group,an ethyl group, an isopropyl group and a t-butyl group; a cycloalkylgroup having 3 to 20 carbon atoms such as a cyclopropyl group, acyclopentyl group and a cyclohexyl group; an alkoxy group having 1 to 12carbon atoms such as a methoxy group, an ethoxy group and an isopropoxygroup; a haloalkyl group having 1 to 12 carbon atoms such as atrifluoromethyl group; a haloalkoxy group having 1 to 12 carbon atomssuch as a trifluoromethoxy group; an aryl group having 6 to 12 carbonatoms that may have a substituent, such as a phenyl group, a4-methylphenyl group, a 2,4-dimethylphenyl group, a 2-chlorophenyl groupand a 3-methoxyphenyl group; an amino group; a monosubstituted aminogroup such as a methylamino group; a disubstituted amino group such as adimethylamino group; an imino group; and the like.

Specific examples of the L³ include a group that is an alkyl grouphaving 1 to 12 carbon atoms in which R³ may have a substituent, such asa 1,1,1,3,3,3-hexafluoro-2-propoxy group, a 2-methyl-2-propoxy group, a1,1,1-trifluoro-2-methyl-2-propoxy group, a1,1,1-trifluoro-2-trifluoromethyl-2-propoxy group and a2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy group; and a group thatis an aryl group having 6 to 30 carbon atoms in which R³ may have asubstituent, such as a 2,6-bis(2,4,6-trimethylphenyl)phenoxy group, a2,6-bis(2,4,6-triisopropylphenyl)phenoxy group, a 2,4,6-trimethylphenoxygroup and a 2,3,5,6-tetraphenylphenoxy group.

L⁴ is a neutral conjugated heterocyclic ligand having at least twonitrogen atoms and having 12 to 24-membered rings. Specific examples ofthe ligand include 2,2′-bipyridyl, 5,5′-dimethyl-2,2′-bipyridyl,4,4′-dimethyl-2,2′-bipyridyl, 4,4′-dibromo-2,2′-bipyridyl,2,2′-biquinoline, 1,10-phenanthroline and terpyridine.

In addition, the conjugated heterocyclic group of the L⁴ may have asubstituent. Examples of the substituent include the same substituentsas listed as the substituents that may be included in the conjugatedheterocyclic group of the L².

Specific examples of the tungsten compound used in the present inventioninclude, but are not limited to,(2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)2,6-dimethylphenylimidetungsten (VI) (2,5-dimethylpyrrolide) (neophylidene)(1,10-phenanthroline),(2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)phenylimide tungsten(VI) (2,5-dimethylpyrrolide) (neophylidene) (1,10-phenanthroline),(2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)2,6-dimethylphenylimidetungsten (VI) (2,5-dimethylpyrrolide) (neophylidene) (2,2′-bipyridine),(2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)phenylimide tungsten(VI) (2,5-dimethylpyrrolide) (neophylidene) (2,2′-bipyridine), and thelike.

In addition, the tungsten compound used as a polymerization catalyst hasa neutral conjugated heterocyclic ligand, and may be used in combinationwith a metal salt compound for increasing the rate of the ring-openingpolymerization of dicyclopentadiene. By combining a metal salt compound,the neutral conjugated heterocyclic ligand can be separated from group 6transition metal compounds in the periodic table to form highly activecatalyst species.

As the metal atom constituting the metal salt, zinc, tin, copper,titanium, rare earth and the like are suitable. Specific examples of themetal salt that may be used include zinc chloride, copper chloride, tinchloride, titanium chloride, scandium chloride, yttrium chloride and thelike.

These group 6 transition metal compounds in the periodic table can beproduced e.g. in accordance with the method described inJP-T-2014-T-520103 (WO 2012/167171) or the like. Also, thosecommercially available as group 6 transition metal compounds in theperiodic table can be purified and used, as desired.

In the method for producing the dicyclopentadiene ring-opening polymeraccording to one embodiment of the invention, dicyclopentadiene or thelike and a polymerization catalyst may be mixed for ring-openingpolymerization of dicyclopentadiene or the like.

Although the amount of the polymerization catalyst to be used relativeto dicyclopentadiene and the like is not particularly limited, the molarratio of the tungsten compound in the polymerization catalyst:dicyclopentadiene and the like is preferably 1:10 to 1:2,000,000, morepreferably 1:200 to 1:1,000,000, and particularly preferably 1:500 to1:500,000. If the amount of the polymerization catalyst to be used istoo large, it may be difficult to remove the polymerization catalyst,and if the amount of the polymerization catalyst to be used is toosmall, sufficient polymerization activity may not be obtained.

The polymerization reaction may be effected in a solvent-free system,but preferably in an organic solvent from the viewpoint that thereaction can be advantageously controlled. The organic solvent used inthis case is not particularly limited as long as the organic solvent candissolve or disperse the resulting ring-opening polymer and does notadversely affect the polymerization reaction. Specific examples of theorganic solvent that may be used include an aliphatic hydrocarbon suchas pentane, hexane and heptane; an alicyclic hydrocarbon such ascyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane,trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane,decahydronaphthalene, bicycloheptane, tricyclodecane,hexahydroindenecyclohexane and cyclooctane; an aromatic hydrocarbon suchas benzene, toluene and xylene; a halogen-containing aliphatichydrocarbon such as dichloromethane, chloroform and 1,2-dichloroethane;a halogen-containing aromatic hydrocarbon such as chlorobenzene anddichlorobenzene; a nitrogen-containing hydrocarbon such as nitromethane,nitrobenzene and acetonitrile; an ether such as diethyl ether andtetrahydrofuran; an aromatic ether such as anisole and phenetole; andthe like. Among these, an aromatic hydrocarbon, an aliphatichydrocarbon, an alicyclic hydrocarbon, an ether, and an aromatic etherare preferably used.

When effecting the polymerization reaction in the organic solvent, theconcentration of the monomer in the reaction system is not particularlylimited, but is preferably 1 to 50 wt %, more preferably 2 to 45 wt %,and particularly preferably 3 to 40 wt %. If the concentration of themonomer is too low, productivity may decrease, and if the concentrationof the monomer is too high, the viscosity of the reaction solution mayincrease to a too large extent after completion of the polymerizationreaction, and it may be difficult to effect the subsequent hydrogenationreaction.

The polymerization temperature is not particularly limited, but isnormally −30 to +200° C., and preferably 0 to 180° C. Further, thepolymerization time is also not particularly limited, but is normallyselected within the range of 1 minute to 100 hours.

When effecting the polymerization reaction, a vinyl compound or a dienecompound may be added to the polymerization reaction system in order toadjust the molecular weight of the resulting dicyclopentadienering-opening polymer.

The vinyl compound used for adjusting the molecular weight is notparticularly limited as long as the vinyl compound is an organiccompound having a vinyl group. For example, α-olefins such as 1-butene,1-pentene, 1-hexene and 1-octene; styrenes such as styrene andvinyltoluene; ethers such as ethyl vinyl ether, i-butyl vinyl ether andallyl glycidyl ether; a halogen-containing vinyl compound such as allylchloride; an oxygen-containing vinyl compound such as allyl acetate,allyl alcohol and glycidyl methacrylate; a nitrogen-containing vinylcompound such as acrylamide; a silicon-containing vinyl compound such asvinyltrimethylsilane, allyltrimethylsilane and vinyltrimethoxysilane;and the like can be used.

Further, the diene compound used for adjusting the molecular weight isnot particularly limited. For example, a non-conjugated diene such as1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene,2-methyl-1,4-pentadiene and 2,5-dimethyl-1,5-hexadiene; a conjugateddiene such as 1,3-butadiene, 2-methyl-1,3-butadiene,2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and 1,3-hexadiene; and thelike can be used.

The amount of the added vinyl compound or diene compound may bedetermined depending on the intended molecular weight, but is normallyselected within a range of 0.1 to 10 mol based on 100 mol of thedicyclopentadiene and the like used as the monomer.

In the present invention, the ring-opening polymerization reaction ofdicyclopentadiene can be effected under the above-mentioned conditionsusing a polymerization catalyst including the tungsten compoundrepresented by the above formula (1) to obtain a dicyclopentadienering-opening polymer having syndiotacticity.

In addition, the dicyclopentadiene ring-opening polymer having thissyndiotactic structure can be subjected to hydrogenation reaction toobtain a hydrogenated syndiotactic crystalline dicyclopentadienering-opening polymer having syndiotacticity as well as crystallinity.

Note that the dicyclopentadiene ring-opening polymer may be collectedfrom the reaction solution, and then subjected to the hydrogenationreaction, or the reaction solution including the dicyclopentadienering-opening polymer may be subjected directly to the hydrogenationreaction.

The number average molecular weight (Mn) of the dicyclopentadienering-opening polymer to be subjected to the hydrogenation reactiondetermined by ¹H-NMR is not particularly limited, but is preferably1,000 to 1,000,000, and more preferably 2,000 to 800,000. A hydrogenatedsyndiotactic crystalline dicyclopentadiene ring-opening polymer thatexhibits particularly an excellent balance between formingprocessability and heat resistance, can be obtained by subjecting thedicyclopentadiene ring-opening polymer having such a number averagemolecular weight to the hydrogenation reaction. The number averagemolecular weight of the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer can be regulated by adjusting theaddition amount or the like of the molecular weight modifier to be usedin polymerization.

The cis content in the dicyclopentadiene ring-opening polymer to besubjected to the hydrogenation reaction determined by ¹H-NMR ispreferably higher than 50%, more preferably higher than 70%, andparticularly preferably higher than 90%.

In the dicyclopentadiene ring-opening polymer, the ratio of the racemodiads is preferably higher than 90%, more preferably higher than 91%,particularly preferably higher than 92%. When the cis content is higherthan 50% and the ratio of the racemo diads is higher than 90%, thesolubility of the dicyclopentadiene ring-opening polymer in an organicsolvent increases, and the producing process for directly subjecting thereaction solution including the dicyclopentadiene ring-opening polymerto hydrogenation reaction is advantageous, and thus the ratio ispreferable.

As described above, the dicyclopentadiene ring-opening polymer accordingto one embodiment of the invention that may be used as an intermediateof the hydrogenated syndiotactic crystalline dicyclopentadienering-opening polymer according to one embodiment of the invention,dissolves in an organic solvent at room temperature. In particular, fromthe viewpoint of the production process in which the polymerizationreaction is carried out in an organic solvent and the organic solventreaction solution including the dicyclopentadiene ring-opening polymeris directly subjected to the hydrogenation reaction, it is preferable todissolve the polymer in an organic solvent inert to hydrogenation.

Examples of the solvent for dissolving the dicyclopentadienering-opening polymer according to one embodiment of the inventioninclude an alicyclic hydrocarbon such as cyclopentane, cyclohexane,methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane,ethylcyclohexane, diethylcyclohexane, decahydronaphthalene,bicycloheptane, tricyclodecane, hexahydroindenecyclohexane andcyclooctane; an aromatic hydrocarbon such as benzene, toluene andxylene; a halogen-containing aliphatic hydrocarbon such asdichloromethane, chloroform and 1,2-dichloroethane; a halogen-containingaromatic hydrocarbon such as chlorobenzene and dichlorobenzene; an ethersuch as diethyl ether and tetrahydrofuran; an aromatic ether such asanisole and phenetole; and the like.

In the method for producing the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention, the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer is obtained by a process (a) inwhich a hydrogenating agent is added to a system including thedicyclopentadiene ring-opening polymer obtained as above, then heatedand reacted, or a process (b) in which a hydrogenation catalyst is addedto the system, to which hydrogen is then added to hydrogenate thecarbon-carbon double bond included in the dicyclopentadiene ring-openingpolymer. Among them, from the viewpoint of industrial production, theprocess (b) in which the hydrogenation is carried out using thehydrogenation catalyst and the hydrogen gas, is preferable.

When conducting the method for producing the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention, in the process (a), it is preferable that ahydrazine-containing compound as a hydrogenating agent for a transferhydrogenation is used to hydrogenate the carbon-carbon double bondincluded in the dicyclopentadiene ring-opening polymer.

The compound used as a hydrogenating agent for a transfer hydrogenationis not particularly limited. The compound used as a hydrogenating agentfor the hydrogenated dicyclopentadiene ring-opening polymer may be acompound used as a hydrogenation catalyst. Specific examples of thehydrogenating agent include hydrazine, paratoluenesulfonyl hydrazide andthe like.

In the present invention, for the hydrogenation catalyst used in theprocess (b), a conventionally known catalyst can be used as ahydrogenation catalyst for ring-opening polymers. Specific examples ofthe catalyst include RuHCl(CO)(PPh₃)₃, RuHCl(CO)[P(p-Me-Ph)₃]₃,RuHCl(CO)(PCy₃)₂, RuHCl(CO)[P(n-Bu)₃]₃, RuHCl(CO)[P(i-Pr)₃]₂,RuH₂(CO)(PPh₃)₃, RuH₂(CO)[P(p-Me-Ph)₃]₃, RuH₂(CO)(PCy₃)₃,RuH₂(CO)[P(n-Bu)₃]₃RuH(OCOCH₃)(CO)(PPh₃)₂, RuH(OCOPh)(CO)(PPh₃)₂,RuH(OCOPh-CH₃)(CO)(PPh₃)₂, RuH(OCOPh-OCH₃)(CO)(PPh₃)₂,RuH(OCOPh)(CO)(PCy₃)₂, Raney nickel, nickel diatomaceous earth, nickelacetate, palladium acetate, PdCl₂, RhCl(PPh)₃, and the like.

The hydrogenation reaction is normally effected in an inert organicsolvent. Examples of the inert organic solvent that may be used includean alicyclic hydrocarbon such as cyclopentane, cyclohexane,methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane,ethylcyclohexane, diethylcyclohexane, decahydronaphthalene,bicycloheptane, tricyclodecane, hexahydroindenecyclohexane andcyclooctane; an aromatic hydrocarbon such as benzene, toluene andxylene; a halogen-containing aliphatic hydrocarbon such asdichloromethane, chloroform and 1,2-dichloroethane; a halogen-containingaromatic hydrocarbon such as chlorobenzene and dichlorobenzene; an ethersuch as diethyl ether and tetrahydrofuran; an aromatic ether such asanisole and phenetole; and the like.

In the method for producing the hydrogenated crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention, preferably hydrogen is further added to a systemincluding a dicyclopentadiene ring-opening polymer and a hydrogenationcatalyst to hydrogenate the carbon-carbon double bond included in thenorbornene-based ring-opening polymer. The hydrogenation reaction mayalso be effected under different conditions depending on thehydrogenation catalyst system to be used, but the reaction temperatureis normally −20 to +250° C., preferably −10 to +220° C., and morepreferably 0 to +200° C. If the hydrogenation temperature is too low,the reaction rate may become too slow. If the hydrogenation temperatureis too high, a side reaction may occur. In a case of catalytichydrogenation, the hydrogen pressure is normally set to 0.01 to 20 MPa,preferably 0.05 to 15 MPa, and more preferably 0.1 to 10 MPa. If thehydrogen pressure is too low, the hydrogenation rate may become tooslow. If the hydrogen pressure is too high, a reactor that can endurehigh pressure is necessary, and in this respect, restriction of theapparatus is caused. The reaction time is not particularly limited aslong as the hydrogenation ratio is suitable as desired, but is normally0.1 to 10 hours. After completion of the hydrogenation reaction, thedesired hydrogenated crystalline norbornene-based ring-opening polymermay be simply collected using an ordinary method. When collecting thepolymer, the residual catalyst may be removed by filtration or the like.

The hydrogenation ratio of the ring-opening polymer in the hydrogenationreaction (the ratio of the hydrogenated main-chain double bonds) is notparticularly limited, but is preferably 98% or higher, more preferably99% or higher, and particularly preferably 99.5% or higher. Theresulting hydrogenated syndiotactic crystalline dicyclopentadienering-opening polymer exhibits better heat resistance, as thehydrogenation ratio increases.

In addition, the tacticity of the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer is not particularly limited aslong as the hydrogenated product has crystallinity (i.e. the meltingpoint is 280° C. or higher) and is syndiotactic (the ratio of the racemodiads is higher than 90%), but the ratio of the racemo diads for therepeating unit of dicyclopentadiene can also be higher than 91%.

The hydrogenated syndiotactic crystalline dicyclopentadiene ring-openingpolymer obtained by the production method according to one embodiment ofthe invention has a high melting point and a high initial meltingtemperature. Thus, this hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer may exhibit excellent heatresistance even after formed by melt forming, and it can be particularlyadvantageously used as a material of a formed article requiring heatresistance. The formed article can be produced according to a knownmethod.

Examples of the applications of the formed article include, but are notlimited to, an optical reflector, an insulating material, an opticalfilm, a connector, a food packaging material, a bottle, a pipe, a gear,fibers, a nonwoven fabric, and the like.

EXAMPLES

Next, the invention will be further described below by way of examples,but the invention is not limited to the following examples.

Note that the following measurement methods and evaluation methods wereused in connection with the examples.

(1) Number Average Molecular Weight of Dicyclopentadiene Ring-OpeningPolymer

The ratio of the number of hydrogen atoms present at the terminals ofthe polymer chain to the number of hydrogen atoms present in the polymerchain excluding the terminals was calculated based on the ¹H-NMRmeasurement results, and the number average molecular weight of thedicyclopentadiene ring-opening polymer was calculated based on thecalculated ratio.

(2) Cis/Trans Content in Dicyclopentadiene Ring-Opening Polymer

Determination was carried out based on the ¹H-NMR measurement results.

(3) Hydrogenation Ratio of the Dicyclopentadiene Ring-Opening Polymer inHydrogenation Reaction

Determination was carried out based on the ¹H-NMR measurement results.

(4) Melting Point and Initial Melting Temperature of HydrogenatedSyndiotactic Crystalline Dicyclopentadiene Ring-Opening Polymer

The hydrogenated dicyclopentadiene ring-opening polymer was molten byheating at 320° C. for 10 minutes, then cooled at 10° C./minute to roomtemperature to crystallize it, and then subjected to measurement byusing a differential scanning calorimeter while heating at 10°C./minute. In an endothermic peak observed at the time of themeasurement with rising temperature, the temperature at which theendothermic (crystal melting) heat flow was the largest, was defined asthe melting point, and the start temperature for the endothermic peakwas determined as the initial melting temperature.

(5) Ratio of Racemo Diads in Hydrogenated Syndiotactic CrystallineDicyclopentadiene Ring-Opening Polymer

¹³C-NMR measurement at 200° C. was carried out usingo-dichlorobenzene-d₄/trichlorobenzene (mixing ratio (weight basis): 1/2)as a solvent, and the ratio of the racemo diads was determined based onthe a peak area value of the signal at 43.35 ppm attributed to the mesodiads and a peak area value of the signal at 43.43 ppm attributed to theracemo diads.

(6) Solder Immersion Test of Hydrogenated Syndiotactic CrystallineDicyclopentadiene Ring-Opening Polymer

The hydrogenated syndiotactic crystalline dicyclopentadiene ring-openingpolymer as a sample was molten by heating at 320° C. for 10 minutes,formed into a shape of 10 mm×100 mm×1 mm and then cooled to roomtemperature at a rate of 10° C./minute, and the resulting sample piecewas immersed in solder at 260° C. for 20 seconds, and the presence orabsence of deformation was evaluated in accordance with the followingcriteria. A case without visible deformation can be evaluated as“excellent in heat resistance”.

[Evaluation Criteria]

“Good”: No visible deformation

“Bad”: Visible deformation

(7) Curling Value of Hydrogenated Syndiotactic CrystallineDicyclopentadiene Ring-Opening Polymer

One end of the sample piece subjected to the solder immersion test wasplaced on a horizontal plane, and the distance between the other end inthe longitudinal direction of the sample piece and the horizontal planewas measured, and the measured value was defined as a curling value. Itwas determined that the sample piece exhibited better heat resistance asthe curling value decreased.

[Synthesis Example 1] (Synthesis of Catalyst (A))

As a bispyrrolide precursor, 312 mg (0.5 mmol) of W(CHCMe₂Ph)(NAr^(diMe)) (Me₂Pyr)₂ (wherein Me represents a methyl group, Phrepresents a phenyl group, Ar^(diMe) represents a 2,6-dimethylphenylgroup, and Me₂Pyr represents 2,5-dimethylpyrrole) was dissolved in 5 mlof benzene, to which 84 μl (0.5 mmol) of α,α-bistrifluoromethylbenzylalcohol [Ph(CF₃)₂COH] was added, and the whole content (reactionmixture) was stirred at room temperature (20° C.) for 30 minutes. Then,90 mg (0.5 mmol) of 1,10-phenanthroline was added, the whole content wasstirred at room temperature (20° C.) for 1 hour, and then the reactionmixture was transferred into a freezer. 10 ml of pentane was added tothe reaction mixture to quantitatively precipitate the reaction product.The reaction product was taken by filtration as an orange solid. Thisproduct was washed with pentane and dried. The yield was 480 mg(quantitatively).

This product was identified as(2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)-2,6-dimethylphenylimidetungsten (VI) (2,5-dimethylpyrrolide) (neophylidene)(1,10-phenanthroline) by ¹H-NMR, ¹³C-NMR and ¹⁹F-NMR spectra of theresulting solid.

Example 1

A glass reactor equipped with a stirrer was charged with 0.072 g (1/500mol/mol) of(2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)-2,6-dimethylphenylimidetungsten (VI) (2,5-dimethylpyrrolide) (neophylidene)(1,10-phenanthroline) obtained in Synthesis Example 1 and 1 g oftoluene, to which 5.0 g of dicyclopentadiene, 20.0 g of cyclohexane and0.21 g of 1-hexene were subsequently added, and furthermore 0.0105 g ofanhydrous zinc chloride dissolved in 5 g of 1,4-dioxane was added, whichwas subjected to polymerization reaction at 50° C. After the start ofthe polymerization reaction, a white turbidness of 1,10-phenanthrolinezinc was rapidly produced. After 3-hour reaction, a large quantity ofacetone was poured into the polymerization reaction solution toaggregate a precipitate, the aggregate was filtered off, washed, andthen dried under reduced pressure at 40° C. for 24 hours. Adicyclopentadiene ring-opening polymer obtained had a yield of 4.3 g,had a number average molecular weight of 14,000, and a cis content of97%.

Subsequently, a glass reactor equipped with a stirrer was charged with2.5 g of the resulting dicyclopentadiene ring-opening polymer and 21 gof para toluenesulfonyl hydrazide were added, to which 500 ml ofp-xylene was added, and hydrogenated at 125° C. for 5 hours. Thishydrogenation reaction solution was poured into a large quantity ofmethanol to completely precipitate the resulting hydrogenateddicyclopentadiene ring-opening polymer, which was filtered off, washed,and then dried under reduced pressure at 40° C. for 24 hours.

The hydrogenation ratio of the resulting hydrogenated ring-openingpolymer was 99% or higher, and the ratio of racemo diads was 92%. As aresult of measuring the melting point of the hydrogenated product, themelting point was 282° C., the melting enthalpy was 53 Jig, and theinitial melting temperature was 275° C. In addition, a solder immersiontest and a curling value measurement were carried out for thehydrogenated product. The results are shown in Table 1.

Example 2

In an autoclave equipped with a stirrer, 1.75 g of a polymerizationmixture of the dicyclopentadiene ring-opening polymer obtained inExample 1 and 47 g of cyclohexane, were added. Then, a solution in which0.00157 g of RuHCl(CO)(PPh₃)₃ was dispersed in 10 ml of cyclohexane wasfurther added, and a hydrogenation reaction was carried out under ahydrogen pressure of 4.0 MPa at 160° C. for 8 hours. The hydrogenatedring-opening polymer produced by pouring this hydrogenation reactionsolution into a large amount of acetone was completely precipitated,filtered out, washed, and then dried under reduced pressure at 40° C.for 24 hours.

The hydrogenation ratio of the resulting hydrogenated ring-openingpolymer was 99% or higher, and the ratio of racemo diads was 92%. As aresult of measuring the melting point of the hydrogenated product, themelting point was 284° C., the melting enthalpy was 52 Jig, and theinitial melting temperature was 274° C. In addition, a solder immersiontest and a curling value measurement were carried out for thehydrogenated product. The results are shown in Table 1.

TABLE 1 Example 1 2 Hydrogenation ratio (%) 99%≤ 99%≤ Syndiotacticity 9292 [Ratio of racemo diads (%)] Melting point (° C.) 282 284 Initialmelting temperature (° C.) 275 274 Solder immersion test Good GoodCurling value 0 0

As is apparent from Table 1, the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer according to one embodiment ofthe invention was proved to be a material that had a high melting point,a high initial melting temperature and excellent heat resistance, notthermally deformed even if brought into contact with solder, and allowedimplementation of solder reflow and the like (Examples 1 and 2).

Consequently, according to the present invention, a hydrogenatedsyndiotactic crystalline dicyclopentadiene ring-opening polymer that hasa high melting point, a high initial melting temperature and excellentheat resistance after melting and is not thermally deformed even ifbrought into contact with solder, can be obtained.

The invention claimed is:
 1. A hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer having a melting point of 280° C.or higher, an initial melting temperature of 260° C. or higher and asyndiotacticity of higher than 90%.
 2. A method for producing thehydrogenated syndiotactic crystalline dicyclopentadiene ring-openingpolymer according to claim 1, including a step of subjecting asyndiotactic dicyclopentadiene ring-opening polymer having asyndiotacticity of higher than 90% to hydrogenation reaction.
 3. Aformed article comprising the hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer according to claim
 1. 4. A methodfor producing the formed article according to claim 3, including a stepof forming the hydrogenated syndiotactic crystalline dicyclopentadienering-opening polymer having a melting point of 280° C. or higher, aninitial melting temperature of 260° C. or higher and a syndiotacticity,of higher than 90%.
 5. The hydrogenated syndiotactic crystallinedicyclopentadiene ring-opening polymer of claim 1 wherein an upper limitof the initial melting temperature is approximately 310° C. and is lowerthan the melting point.